Multiple well drilling apparatus and method



June 24, 1958 c. JENKINS ETAL 2,840,197

MULTIPLE WELL DRILLING APPARATUS AND METHOD Filed oct. 19. 1955 5 Sheets-Sheet 1 l F3 P92 NVEN 0 #unav wwmye'c 5 6 6 BY Poseer c: mannen.

June 24, 1958 QJENKINS ETAL 2,840,197

MULTIPLE WELL DRILLING APPARATUS AND METHOD Filed Oct. 19, 1955 5 Sheets-Sheet 2 June 24, 1958 c. JENKINS ErAI. 2,840,197

MULTIPLE WELL DRILLING APPARATUS AND METHOD Filed Oct. 19, 1955 5 Sheets-Sheet 5 INVENTORS June 24, 1958 c. JENKINS ETAL 2,840,197

MULTIPLE WELL DRILLING APPARATUS AND METHOD Filed Oct. 19, 1955 5 Sheets-Sheet 4 @n M4@ au@ June 24, 1958 @JENKINS E11-Ax. 2,840,197

MULTIPLE WELL DRLLING APPARATUS AND METHOD Filed Got. 19, 1955 l 5 Sheets-Sheet 5 VENT R6 Circa Me/MJ, 66W om BY MM United States Patent Otice 2,840,197 Patented June 24, 1958 MULTIPLE WELL DRIL'LING APPARATUS AND METHOD v Cecil Jenkins, John Wesley Born, Homer J. Woolslayer, and Robert C. Maxwell, Tulsa, Okla., assignors tovLee C. Moore Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Application October 19, 1955, Serial No. 541,468

19 Claims. (Cl. 189-11) This invention relates to the drilling of two or more oil wells clovsetog'ether without moving the base on which the drilling apparatus is mounted.

For many years ythere have been two general ways of drilling oil wells. Oneway has been to erect a conventional oil well derrick and drill a well with it, and then either leave the derrick for service work' and build a new one for the knext well, or dismantle the derrick and rebuild it at the second well. The other system has been to use a portable mast which is moved from one location to anotherlalong: with its base or substructure and all of the drilling equipment. Recently a new practice has grown up in certain locations, according to which two or moreA wells aredrilled close together without moving the derrick and its basel Modern drilling methods permitr wells4 to be drilled as close asV two feet apart at theirupper ends. As the wells descend :they curve'away fromone another toward the desired underground locations. In such an operation it has been necessary to use a derrick that is large at top" and bottom so that the crown block can be shifted to different locations on top of the derriclctoposition `it overfthe locations of the diiferent wells `that are tor be drilled Within the Vcontines of the bottom of the derrick. .This multiple well drilling practice has developed because off the extremely high cost of preparing drilling sites in such locations as offshore and mountain sides. Such a derrick obviously is a massive and very expensive structure that also has the same objections as conventional derricks used in single well drilling. v Y

lt is vamong the objects of this invention is to provide a method and apparatus for drilling a plurality of closely spaced wells without moving the base that supports the drilling equipment,l in which a portable` mast is used that is no larger than necessaryfor drilling a single well, and in which the mast can readilybe moved along thebase from one well` location to another without lowering the mast. -K j AIn accordance with this invention a substructure or base is provided'which can be placed in'xed position over the site of a; line of two orymore wells that are to be drilled. Anupright drilling mast is located on the base in position to drill a well. yMounted on the base, beside the mast, there is a Vginpole which is lused in raising the mastand supporting it. There is a pivotal connection on the base for the lower'fend of the mast and an- Votherpivotal connection for the mast' at the top of the gin pole. After a well has been drilled, the mast is tilted on one of those pivotal connections and then it is swung upright again on the other pivotal connection. In this way 'the mast can gbe moved or walked along the base in a straight line .to drill one well after another. The mast and gin pole *are` connected together at each well. The gin pole may be movable along the base in'- dependently of the mast or be carried by it, or the gin pole may be made large enough to permit it to remain in One position whileA the mast is walked along the base.

When all of the drilling has been completed, the gin pole aids in swinging the mast down to reclining position for removal from the base.

The invention is illustrated in the accompanying drawings, in which Fig. 1 is a side view of our well drilling apparatus;

Fig. 2 is a front view thereof;

Fig. 3 is an enlarged detail in section of the pivotal connection between the mast and the' top of the gin pole;

Figs. 4, 5 and 6 are schematic views illustrating how the mast and gin pole are moved along the base from one well to another;

Figs. 7, 8 and 9 are similar views of a modification; Y

Figs. 10 and 11 are schematic views of a further enibodiment;

Figs. l2, 13 and 14 are similar views of a still further modification; and

Fig. 15 is an enlarged detail of another type of pivotal connection between mast and gin pole.

Referring to Figs. l and 2 of the drawings, the mast preferably is formed from two laterally Vspaced booms B that are inclinedupwar'dly towards each other' and support a crown block C, from which a traveling block T is suspended. Each boom may have a pair of front legs 1 that come together at their lower ends, anda pair of rear legs 2, the lower ends of which terminateV a considerable distance above the foot of the boom. The lower ends of these rear legs are Connected by diagonal braces 3 with the lower ends of the front legs. The two feet of the mast are pivotally mounted or hinged in shoes 4 supported by a suitable base 5 which generally will be mounted on a larger platform 6. The base extends lengthwise of the line of wells that are to be drilled; that is, the base extends forward from the drawworks (not shown) along the line of wells.

The mast is supported in upright operative position by a gin pole, which consists of a pair of front legs 8 pivoted at their upper ends tok a pair ofback legs 9. The front legs of the gin pole are disposed between the mast booms and the lower ends of those legs are pivoted in shoes 10 on an axis concentric with theA axis of the masthinges. The lower ends of the rear legs are pivoted in shoes 11 connected to the base .behind the mast. Although the rear legs of the gin pole may be connected by cross braces, such braces are not necessary. Nevertheless, the legs of the gin pole Will be referred to herein collectively as the gin pole, even though the opposite sides of the pole are not connected together. n

The mast can be raised to upright position from a reclining position in front of the gin pole by swinging the mast upward on shoes 4 in a well-known manner with the aid of a sling (not shown) secured. to the top of the gin pole and attached to the traveling block. When the mast is upright it is connected to the top of the gin.

pole by suitable removable pivotal means, such as long horizontal pins 13 that slide in sleeves 14 extending through the booms, as shown in Fig. 3. The inner ends of the pins project into collars 15 mounted on top of the gin pole. The pins can be pulled back into the sleeves against the resistance of coil springs 16 therein, by means of lines 17 attached to the pins. f

After the mast has been erected into the position shown in Figs. 1 and 4 and a well I has been drilled, the mast and gin pole can be moved forward on the base to drill a second well II (Fig. 6). According to this invention, such a move is accomplished by guy lines 19 attached to the front and lback of the upper part of the mast and to suitable anchorage points, such as platform 6. After the lines have been secured in order to holdlthe mast upright independently ofthe gin pole, the pivot pins l13 at the top of the gin pole are drawn back into sleeves 14 to release the gin polefrom the mast. The back feet of the gin pole are then disconnected from the base, and the top of the gin pole is swung forward by any suitable means, such as a winch line (not shown) until the front ofthe gin` pole is substantially vertical, as indicated in broken lines in Fig. 4. The rear legs of the pole then are` connected again to the base in their new location, in which they are inclined to the same extent as before so that the top of the gin pole will not have to be moved during the next step. The next step is to `disconnect thc front `legs ofthe gin pole from the base and swing them forward a predetermined distance as shown in broken lines in Fig., 5, and then reconnect them to the base without lowering the head of the. gin pole. In this new or second-location, the front feet of the gin pole should be the same distance from the rearfeet as in the original or rstlocation, but the entire gin pole Iwill be at slightly higher elevation than before. Y

Y. The mast is now tilted forwardxto the broken line position of Fig. 5 by means of the guy lines 19, which may be controlled in` any suitable manner. `For convenience of illustration, they are shown provided with turnbuckles for lengthening andrshortening them. The mast is tilteduntil `pivot pins 13 `are opposite the collars at the top of the gin pole, whereupon the pins are projected into the collars `to reconnect the mast to the gin pole as shownpin full lines in Fig. 6. The pins will register with the collars, because the top of the gin pole was swung through thesame arc as `the pins. The feet-of the mast then are disconnected from` the basev and the rear guy lines are pulled to swing the mast upright again around its pivotal connections to the .top of the gin pole. This moves the feet of the mast forward beside the front feet of the` gin pole, and the mast feetare there reconnected tothe base. It will be seen that the mast, shown in broken lines in Fig. 6, and the gin pole are now in the same positions relative to each other as they were in Figs. l and 4, but both have been moved forward along the base to arlocation where `the Vsecond well II can be drilled.

To keep the `floor of the base as free of obstructions as possible, it is desirable to leave the shoes 4, 10 and 11 connected to fthe mast and gin pole during walking of the mast along the base, so the shoes are disconnected from the base inthe rst location andreconnected to it in the second location. As the gin pole and mast move upward slightly as they move forward, it `must be possible to fasten the shoes to the base at `different elevations. This can easily be done by providing the base with bolt holes for the shoes at higher elevations in the second location of the mast and gin pole than in their first location. However, in order to'illustrate more clearly the different movements of the parts in Figs. 4, 5 and V6, two sets of shoes are shown. One set 4, 10, 11 is in the first or original location ofthe mast and gin pole and they otherset 4', 10', 11 is in second` location'l theless, as just explained, in practice only one set of shoes will generally be used and they will be carriedalong by the mast and gin pole. e The mast moving operation .that has just been described can be repeated as many( times as desired, depending on the length of the base. Thus, a line of three or morewells can be drilled by thisy walking mast, all without moving the base; After the last well has been completed, the mast can be swung forward` and down to reclining position and then disconnected from the base` for transportation to Vanother location. `Of course, if the base is skidded sideways on platform 6,-a second line of wells can be drilledV beside thegiirst line. Beside being able to use a portable one-well mastfthat can be swung up `anddown between reclining `and upright positions, another advantage of this apparatus is that several wells can be drilled withoutrnovingV either the crown block or the base and without lowering the mast.

,In the modification shown in Figs. 7, 8 and 9, the

Neverthe front legs of the gin pole.

upper ends of the front legs of the gin pole are pivotally connectedv to its back legs 26, andthe head of the gin pole is detachably pivoted in any suitable manner at 27 to the opposite sides of the mast between its front and back. After a well I has been drilled by the mast in its original upright position, the feet of the mast are disconnected frorn the base 5 at 28 and the mast is tilted forward on the top gin' pole pivots 27 to the position shown in broken lines in Fig. 7. The feet of the mast then are pivoted to the base again at a point 28 behind The-mast then is disconnected from the head of the gin pole and swung up to upright position (indicated by broken lines in Fig. 8) by guy lines 19,- which ,hold it in this new locationover a second well II while the gin pole is moved back along the base to a second location. i

The gin pole is moved preferably by disconnecting its back legs 26 from the base at 29 and pulling them back to a pointY 29 that .is the same distance behind the mast as the back vfeet of the gin` pole werev behind the mast when they were at point 29 before themast was moved. This places the gin pole in the broken line position shown in Fig. k8. The brokenl line positions ,of the mast and gin pole in Fig. 8 are shown in full lines in Fig. 9. The front feet of the gin pole are then disconnected from the base, and the top of the pole is pulled backward until those feet can be attachedk tothe base at 28 beside thelower end of the mast, as shown in broken lines in Fig.

9. The mast and the top of the gin pole are then conlit) nected together again at27, and the mast is ready for drilling theV second well.

If only two wells are to'be drilledinthis manner, it is not absolutely necessary that the. gin' pole be moved, provided the mast is adequately supported bystrong guy lines in its second position. Of course, insuch a ease,

Vthe mast would have to'bel tilted forward for,V reconnection to the gin pole and then swung up to its original' upright position before it could be lowered to reclining position by a sling attached tothe top of the gin pole In the form of the invention shown in Figs. l0and ll, the mast and gin pole 31 are not disconnected from each other during the walking of the mast from one location to another along the baseS. Thus, as shown in Fig. 10, after a well 1 has been drilled the lower end of the mast is disconnected from the base at 32 and'then the mast isv swung backward on its pivoted connection 33 with the gin pole to the broken line position, by Vmeans of guy lines 19. During this movement, the foot lof the mast is swung forward so that it can be pivoted to the base at 32. The gin pole then is disconnected from the base, and the mast and pole are swung forward together to the broken line position of Fig. 1l. rTo prevent the gin pole from collapsing while suspended from the mast, its front and'rear legs can be spaced apart by spreaders 34. In its forward position, the gin pole is again connected to the base as shown. This new location of the mast is ahead of the original one and in a position for drilling a second wellII.l

Another way of using this construction'is to disconnect the gin pole from the baseV and then swing the top of the mast forward to carry the gin pole ahead. The gin pole is again connected to the base and then the mast is swung backward to tilt it up into upright positon, again-in its new location. If it is desired to move in the opposite direction on the base, the mast can be tilted forward on the gin pole, the foot of the mast hinged to the basc behind its original location, the giny pole disconnected from the base, Vthe mast then swung to the rear into upright position, and theV gin pole which was carried back withthe mast then reconnected to the base.

The gin pole 41 shown in Figs. 12, 13 and 14 is not moved along the base 5 with the mast. Instead, it is made of great enough extent lengthwise of the base to permit the mast to be connected to it in different locations. Starting with the forward position of the mast shown in Fig.- 12, after completion ofthe rst welll I, the mast maybe disconnectedfrom the base and swung forward on its pivotal connection 42 with the gin pole to the broken line position. This moves the foot ,of the mast back behind the well from shoes 43, where the mast is again hinged to the base at 43. The mast then is disconnected from the gin pole and swung backward to upright position over the second well II, as indicated in broken lines in Fig. 13. In vthis position, it is pivotally connected at 44 to the central part of the top, of the gin pole. To drill a third well III, the mast is again disconnected from the base and its lower end swung backward behind the second well as shown in full lines in Fig. 14.

In this position, the mast is connected to the base at 43" Y and disconnected from the gin pole at 44. When the mast is swung backward to upright position (shown in broken lines), it will be over the third well, where it can be connected at 45 to the rear end of the top of the gin pole.

In any of these embodiments of the invention, the pivotal connection shown in Fig. l5 can be substituted for the one in Fig. 3. In this modil'ication'the top of the gin pole 51 is provided with a perforated lug 52 that projects into a bifurcated bracket 53 carried by the mast boom B. A pivot pin 54 extends through the bracket and lug to connect the mast to the gin pole. The pin is secured in one end of a tube 56,k to the opposite end of which a nut 57 is welded. The tube and nut are splined in a horizontal sleeve 58 fastened to the mast.

Threaded in the nut is a screw 59 that has its youter end rotatably mounted in a bracket 61 carried by the mast. A ratchet 62 is mounted on the screw for turning it, so that the pin can be withdrawn from the lug and bracket 53 when it is desired to lower the mast or to swing it backward or forward relative to the head of the gin pole.

According to the provisionsof the patent statutes, we have explained the principle ofour invention and have illustrated and described what we now consider to represent its bestY embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention maybe` practiced otherwise than as specifically illustrated and described.

l. Apparatus for dlillinga line of closely spaced wells,

comprising a base adapted'to be placed in iixed position vover the site of said wells and extendingr lengthwise of of the mast, a pivotal connection for the mast at the top of -the gin pole, andmeans for tilting the mast lengthwise of the baseon one of said pivotal` connections andvthen swinging the'mastV upright again on the other of said pivotal connections, whereby the mast can be moved lengthwise of the base to drill another well.V

`2. Apparatus for drilling a line of closely spaced wells, comprising a base adapted to be placed in fixed position over the site of said wells and extending lengthwise of said line, an uprightdrilling mast on the base in position to drill a well, a gin pole on the base beside the mast, a pivotal connectionl on the baseV forv the lower end ofthe mast, a` pivotal connection for the mast at the top of thegin pole, and means for tilting the mast lengthwise of the base on the base pivotal connection and then swinging the mast upright again on the gin pole pivotal connection, whereby the mast can be moved lengthwise of the base to drill another well.k

3. Apparatus for drilling .a line of closely spaced wells, comprising `a base adapted to be placed in fixed position over the site of said wells and extending lengthwise of said line, an upright drilling maston thebase in position to'drill a well, a gin pole on the base `beside the mast, a pivotal connection on the base for the lower end of the mast, a pivotal connection for the mast at the top of the gin pole, and means for tilting' the mast lengthwise of the base onthe gin then swingingithe mast upright again on the base pivotal connection, whereby the mast can be moved'lengthwis of the base'todrill another well.

4. Apparatus for drilling a line of closely spaced Wells, comprising a base-adapted to be placed in fixed position over thel site of said wells and' extending lengthwise of said line, an upright drilling mast on the base in position to drill a well, a gin pole on the the base' beside the mast, a detachable pivotal connection on the base for the lower end of the mast, a detachable pivotal connection 4Vfor the-mast at the top of the gin pole, and means for tilting the mast lengthwise of the base on one of said pivotal'connections while detached from the other pivotal connectionV and then after detaching the mast from said one connection swinging the mast upright again on the other pivotal connection, whereby the mast can be moved lengthwise of the base to drill another well.

5. Apparatus for drilling a line of closely spaced wells, comprising a base adapted to be placed in xed position over the site of said wells and extending lengthwise of said line, an upright drilling mast on the base in position to drilla well, a gin pole detachably mounted in a first location on the base beside the mast, means detachably hinging the lower end of the mast to the base, the mast being adapted to be swung on said hinging means from a reclining position up to said upright position,means detachably pivoting the upright mast to the top of the gin pole,` means adapted to 'detachably connect the gin pole to the base in a second location along the base, and means for holding the mast while the gin pole is disconnected from it and moved lengthwise of the base to said second location and for tilting the mast lengthwise of the base into position to be pivoted tothe top of the moved gin pole,V the base beingv provided at a point spaced lengthwise thereof from said hinging means with means adapted to receive the lower end of the mast Vafter the mast has been swung on its gin pole connection upright in saidv second location, whereby the mast is movable lengthwise of the base to drill another well. Y

6. Apparatus forv drilling a line of closely spaced wells, comprising a baseadapted to be placed in xed position over'the site of said wells and extending lengthwise of said line, an upright drilling mast on the base in position to drill a` well, a gin pole onthe base beside themast having front and rear pairs of legs supported by the base in a` first location, means detachably hinging the lower end ofwthe mast to the'base, Vmeans detachably pivoting the vmastto the top of the gin pole, means for holding the mast `to-permit the gin pole to be disconnected from it and moved lengthwise .of the base a predetermined distance to a second location, means for detachably pivoting the lower ends of the Vgin pole legs lto the base in either location, means pivotally connecting the top of the rear gin pole legs to the top of its front legs to permit iirst one pair of legs and then the other to be swung from said rst to said second location while. disconnected fromy the mast, and means for tilting the mast lengthwise of the base into position to be pivoted again to the top of the gin polewhen the latter is in the second location, the base being provided at a point spaced lengthwise thereof from vsaid hinging means with means adapted to receive the lower end of thetmast-after the mast has been swung on its gin poletconnection upright -in said second lo'ca-v tion, whereby the mast is movable lengthwise of the base lto drill another well.

7. Multiple well drilling apparatus according to claim 6, in which the pivotal connection of the front ylegs of the gin pole to the base in'said first location is concentric with the axis of saidhinging means;

8. Apparatus for drilling a line of closely spaced wells, comprising a base `adapted to be placed in tixed position over the site of said wells and extending lengthwiseof said line, an upright drillingmast on the base in position to'wdrill awell, a 'gin'pole on the base beside the mast.

pole pivotal connection and either location-means pivotally connecting `the top of the rear gin pole legs to the top ofits front-legs to permit first one pair of legs Vand then theother tol be swung from said first to said second location while disconnected from the mast, and means for tilting the mast forward -into a positionto be pivoted again to the top of the gin pole,

whenthe latter is in the second location, the base being provided `in front of said hinging means with means adapted to receive the lower end of the mast after the mast has been swung on its gin pole connection upright in said second location,` `whereby the mast is movable forward on the base to drill another well. V 9. `Apparatus for drilling a line of closely spaced wells, comprising Va` base adapted to be placed in fixed position over the `site ofl said wells'a'nd extending lengthwise of said line, an upright drilling mast on therbase in position to drill a well, 'a gin pole on the base beside the rnast having front and rear pairs lof legs supported by the base in a first location, means detachably connecting the lower end of the mastto the-base, means detachably pivoting the mast to the top of the gin pole, means for tilting the mast forward on its `gin pole connection and holding it there while `the-gin'pol`efis disconnected from the mast and movedtbackward` on `the `base a predetermined distance to a second location,v means for detachably pivoting the lower ends of the ginl pole legs to the base in either location, `means pivotally connecting the top of the rear gin polelegs to the top of its front legs to permit first one pair of legs and then the other to be swung from said first to said second location while disconnectedfrom the mast, hinging means behind saiddetachable connecting means` fonhinging the lower end of the tilted mast to the base, means for-swinging the tilted mast backward on said hinging means to upright position for connection again tothe top of the gin pole,`whereby the'mastis movable backward on the baseto drill another well.

10. Apparatus for drilling a line of closely spaced wells, comprising a base adapted to be placed in fixed position over thesite of said wells and extending lengthwise of said line, an v"upright drilling mast on the base inposition to drill a well, a ginppole on the base beside the mast in Vauf'irst location,fmeans kdetachably pivoting the lower endofthefrnast to the base, the mast being adapted to 'be 'swung on 'said pivoting means from a reclining position up to said upright position, means detachably pivoting 4the uprightmast to the top of the ginpole, means'` adapted to detachably connect the gin pole to the `bassin asecondlocation along the base, and means for tilting; the mast lengthwise of the base on one of said pivoting means and then swinging `the rnast upright again on the other of-said pivoting means, whereby the mast Vcan `bepmoved lengthwiseof the base to drill another well, the mast remaining connected to the top of the gin pole during said movementof the. mast from said first to said second location in order to carry the gin pole along with it from well to well.. V`

11. Apparatus forV drilling a line of closely spaced wells, comprising a `hase adapted ,to be placed in fixed position over the site of said wells and extending lengthwise `of said line an` `upright drilling mast on Vthe base in position to drill a well, a ginpole on the base beside the mast in a rfirst location, means detachably pivoting the lowervend *of* the mast to the base, the mast being adapted to be swung on `said `pivoting means from a reclining position up to-"said upright position, means detachably `pivoting the upright mast to the top of the gin pole, means adapted to detachably Vconnect the gin pole..to the, basein a secondposition along the base,` means fortilting the mast lengthwise Aof the baseon said mast pivotingmeans, means for detachably pivoting the lower end `of the. tilted 'mast to the base' adjacentsaid scc'ond'location of the .gin pole,i and means for swinging the tilted mastfupright again onsaid last-mentioned pivoting means while the mast and ginfpole remain connected mast tosad secondI location. y 1

l2.' Api, gaius for drilling line. of closely spaced wells,

"ving upper. `part extending lengthwise of the base away from the mast, aset otspaced connections for detachably connectingl the lower end Yof the mast to the base `in a plurality of longitudinally spaced locations, a set of spaced connections for detachably connecting the mast to said upper portof the gin pole in a pluralityof locationsQ-and means for tilting the mast lengthwise-of the hase on a first connection in one of said sets to move the mast from la first to a second connection in the other set, and `for then swinging the mast upright again on said second connection after disconnection of said first connection in said one set, whereby the mast can be moved lengthwise of the base from one upright location to another. l t

13. Apparatus for drilling a. line of closely spaced wells, comprising a base-adapted to be placed in iixed position over the site of said wells and extending lengthwise of said line, an upright drilling mast on the `base in position to drill a well, a gin pole' on the base beside the mast and having an upper part extending lengthwise of the base away from the mast, the base having a plurality of longitudinally spaced pivot points for the lower end of the mast, the upper part of the gin pole having a plurality of pivot points spaced lengthwise ofthe base, and means detachably pivoting the mast to two of said vertically spaced points, the mast being adapted to be swung about gin pole and base pivot points alternately so that the mast can travel along the base from one well to another.

14. In the method of drilling a line of closely spaced 'wells from a mast on a base located in xed position over the site of the wells and extending lengthwise of said line, the steps comprising supporting the mast in upright position to drill the first well, tilting the mast lengthwise of the base to position part of it at a point over an area between the first well and the location for the second well, and then rotating'said mast on said point to swing the mast into upright position for drilling the second well.

15. The method of moving an upright oil well drilling mast and its supporting gin pole lengthwise of a supporting base, comprising holding the mast upright independently of the gin pole, disconnecting the gin pole from the mast and moving the gin pole to another location along the base, tilting the mast toward the'relocated gin pole, pivoting the tilted mast-to the top of the gin pole, and then swinging the bottom of the mast in the same direction that the pin pole wasv moved, whereby to right the'mast.

f 16. The method of moving an upright oil well drilling mast and its supporting gin pole lengthwise of a supportingbase, comprising tilting the mast lengthwise of' the base about an axis at the top of the gin pole, disconnecting the gin pole from the tilted mastand supporting the fmast independently thereof, moving the disconnected gin pole to another location along the base in the direction opposite to the directionin which the mast was tilted, swinging the tiltedA mast on its lower end up to upright position, and then connecting the upright mast to the top of the `relocated gin pole.

i7. The method of moving anupright oil well' drilling f mast and its supporting gin pole lengthwise of a supportlengthwise of the base to carry the gin pole to a new loca,- tion along the base, connecting the gin pole to the base in the new location, disconnecting the mast from the base, and swinging the mast to upright position about an axis at the top of the gin pole.

18. The method of moving an upright oil well drilling mast and its supporting gin pole lengthwise of a supporting base, comprising tilting the mast lengthwise of the base about an axis at the top of the gin pole, pivoting the lower end of the tilted mast to the base, disconnecting the tilted mast from the gin pole, swinging the mast on its lower end up to upright position, and then connecting the upright mast to the top of the gin pole at a point spaced lengthwise of the base from said axis.

(10" 19. The method of moving an uptight oil well drilling mast and its supporting gin pole lengthwise of a supporting base, comprising tilting the mast lengthwise of the References Cited in the le of this patent UNITED STATES PATENTS 2,293,958 Woolslayex` et al Aug. 25, 1942 2,403,080 Hilborn July 2, 1946 

